Screw-cutting attachment.



F. E. ANTHONY.

SCREW CUTTING ATTACHMENT.

APPLICATION FILED" OCT. 12, 1906.

Patented Jan. 11, 1910.

FIG

llll ll STATES AENT rrcii.

FREDERICK E. ANTHONY, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR T0 BROWN ANDSHARPE MANUFACTURING COMPANY, OF PROVIDENCE, RHODE ISLAND, A

CORPORATION OF RHODE ISLAND.

SCREW-CUTTING ATTACHMENT.

Specification of Letters Patent.

Patented Jan. 11, 1910.

Application filed October 12 1906. Serial No. 338,577.

To all whom it may concern:

Be it known that I,"FREDERIOK E. AN- THONY, of Providence, county ofProvidence, and State of Rhode Island, have invented certain new anduseful Improvements in Screw-Cutting Attachments; and I do herebydeclare the following specification, taken in connection with theaccompanying drawings and forming a part of the same, to be afull,clear, and exact description thereof.

The invention relates to an attachment for screw-machines, and has forits object to provide an attachment whereby screwthreads of any form,depth or pitch may be rapidly produced. Ordinarily in these machines thescrews are cut by means of dies, but there is a limit to the depth andpitch of a screw-thread which can be properly. and advantageously cut bya die. Heretofore when it has been desired to produce screws havingthreads of. a greater depth or pitch than could be conveniently cut by adie, it has been customary to cut such screws in a lathe by means of anordinarylathe-tool. But this involves repeated passes of the tool alongthe screw-blank, a greater or less number of passes being requiredaccording to the depth of the thread to be cut.

The object of the present invention isto provide an attachment wherebythreads of a depth or pitch which could not be properly cut by means ofa die may be rapidly produced and with only a single passage of thecutting tool past the work.

To that end the invention consists primarily in a screw-cuttingattachment adapted to be mounted in the toolcarrier of a screwmachineand provided with a rotary cutter and means for rotating the same,whereby as the cutter is moved along the work, or the work is movedlengthwise with relation to the cutter, a thread is progressively cutthereon to the desired depth by the action of the successive teeth ofsaid rotary cutter.

A further feature of the invention consists in the employment in such ascrewcutting attachment of a master-screw for revolving the rotarycutter and controlling the pitch of the thread to be out thereby.

A further feature of invention consists in providing means for rotatingthe rotary i cutter from the work-spindle of the machine through thework carried thereby.

'A further feature of invention consists in providing means forcontrolling the rotation of the cutter by the movements of thereciprocating tool-carrier in which the rotary cutter is mounted, thearrangement being such that as the tool-carrier advances to bring therotary cutter up to the work the rotary cutter will be caused toberotated, the further advancing movement of the toolcarrier serving tomove the rotating cutter along the work to cut the screw-thread thereon.

The invention further consists in certain features of construction andin combinations and arrangements of parts hereinafter described and setforth in the claims.

Referring to the drawings, Figure 1 is a plan view of the attachment,showing also the end of the work-spindle of a screw-machine with the rodof stock from which the screws are to be formed projecting therefrom;Fig. 2 is a longitudinal section on the line \-B. Fig. 1: Fig. 3 is anend view of the attachment; Fig. 4 is a section on the line -.D. Fig. 1;Fig. 5 is a section on the line 1*1F, Fig. 1; Fig. 6 is a section on theline G-H, Fig. 1; and Fig. 7 is a detail showing the operation of therotary cutter in cutting the thread.

1 represents the rotating work-spindle of a screw-machine, and 2 the rodof stock held therein from which the screws are to be made.

3 represents the attachment as a whole, said attachment being rovidedwith a shank 4, by which it may i e held in the toolcarrier of themachine. The attachment also embodies a frame or casing 5 in which therotary cutter and the other operating parts are mounted.

Mounted to revolve in the frame 5 is a spindle 6 provided with a screw7. Said screw 7 engages a worm-wheel 8 secured to a short shaft 9mounted to revolve in the frame. Secured to said shaft 9 isa gear 10which meshes with an intermediate idler gear 11, which latter gearmeshes with a gear 12 secured to the shaft 13 mounted in the frame. Tosaid shaft 13 is secured the rotary cutter 14.

the drawings for adjusting the shafts 9 and 13 and holding them inproper position which it will not be necessary to describe in detail.

5 The forward end of the screw-spindle 6 is tapered and adapted to entera recess 15 formed in the end of the rod of stock 2, and preferably theend of said spindle is made triangular or of other polygonal form 10 incross section as shown, in order that when said spindle is, by theadvancing movement of the tool-carrier, brought into e11- gagement withsaid rod there may be a practically positive connection betwen the 15rod and said spindle to revolve the latter.

In order to cut a screw-thread upon the rod of stock it is necessarythat the toolcarrier shall continue to advance after the screw-spindlehas been brought into engagement with the rod of stock, and to enablethis to be done said screw-spindle is mounted in the frame 5 so as to bemovable lengthwise with relation to said frame and the other partscarried thereby. As shown in Fig. 2, the rear end of the screw-spindle 6is mounted in a bearing 16 secured in the shank 4. Said shank 4 is madehollow and mounted therein in rear of the screw-spindle is a hollowsleeve 17, within which is mounted a spring pressed plunger 18, havingthe spring 19 surrounding the shank of said plunger and bearing at oneend against the head 20 of the plunger and at the other end against theclosed end 21 of the sleeve 17 With the construction and arrangement ofparts above described the operation is as follows: By the advancingmovement of the tool-carrier carrying the screw-cutting attachment thetapered end of the screwspindle 6 is brought into operative engagementwith the rod of stock which is rotated by the work-spindle, and so thatthe rotary movement of said wor -spindle and the rod carried therebywill be imparted to said screw-spindle, which will be thus rotated bythework-spindle through the rod of stock' and at the same speed as saidrod. The rotation of said screw-spindle causes a corresponding rotationof the worm-wheel 8, and through the interposed gearing of therotary-cutter 14. The parts are so constructed and arranged that when,by the advancing movement of the tool-carrier, the tapered end of thescrew-spindle has been brought into engagement with the rod of stock,and the rotary cutter thereby caused to be rotated, said rotary cutterwill be in proper position, as shown in Fig. 1, to begin the operationof cutting a screwthread on the rod. As the tool-carrier continues toadvance, the frame 5 and all the parts mounted therein willbeiadvance'd,"except the screw-spindle '6 and the springpressed plunger18, which will be prevented ,from advancing farther by reason of theengagement of the end of the screw-spindle with the rod of stock whichis firmly held by the jaws of the chuck in the work-spindle, the furtheradvance of the other parts being permitted by the yielding of the spring19. 0 The continued advance of the tool-carrier referred to causes theworm-wheel 8 to travel along the screw 7 and this imparts a slightrotation to said worm-wheel in addition to the rotary movement impartedthereto by the rotation of the screw, but this additional rotarymovement of the worm-wheel is also transmitted through the interposedgears to the rotary cutter.

It is preferred to make the rotary cutter 0 and the Worm-wheel of thesame size, that is, with the same number of teeth in each, and also tomake the gears 10 and 12 of equal size. If desired, however, the numberof teeth in the rotary cutter may be some muls5 tiple of the number ofteeth in the wormwheel, in which case the ratio of the gears 10 and 12should be made to correspond, and so that the rotary cutter will at alltimes be revolved in unison with the worm-Wheel.

With the construction above described, as will be seen, the screw 7,which may be termed the master-screw, is revolved by the rod of stockand is consequently revolved, and must be revolved, at the same s eed assaid rod and in unison therewith. t 0 also any advancing movement of theworm-wheel 8- engthwise with relation to the master- ;screw isaccompanied by a corresponding advancing movement of the rotary cutterlengthwise with relation to the rod of stock. Consequently with theworm-wheel revolved, as it is, by the master-screw, and with the rotarycutter revolved through the interposed gearing in unison with saidwormwheel, the pitch of the thread cut by the rotary cutter upon the rodwill be controlled by, and will correspond with, the pitch of themaster-screw. In order, -therefore, to cut a screw of any d esired pitchit is simply necessary to employ a master screw of the pitch required,the worm-wheel and rotary cutter being changed to correspond, and itwill be seen that with the construction shown the master-screw may bereadily. removed 1 and another substituted in its place. It will befurther seen that the rotation of the master-screw and of the rotarycutter is inter- -mittently effected by the advancing and retractingmovements of the tool-carrier in which the. screwcutting attachment is'mounted, and also that the construction is such that the attachment andits operating parts, with the exception of the masterscrew, may continueto advance and so as to carry the rotary cutter lengthwise along 7 therod of stock, after the spindle of the master-screw has been broughtinto engagement with said rod and caused to be rotated therewith.

As will be understood the cutting of the screw-thread upon the rod ofstock will be progressively ett'ectcd to the desired depth by the actionof the successive teeth of the rotary cutter as said cutter isadvancedalong said rod and rotated by the master- 'screw, and the cutting of thecomplete thread will be accomplished by a single passage of the rotarycutter.

In the above description of the operation of the attachment shown it hasbeen assumed that the attachment was employed in connection with ascrew-machine in which the tool-carrier is advanced and retracted towardand from the work-spindle. It will be understood, however, that theattachment may also be employed in a machine in which the Work-spindleis advanced and retracted toward and from the tool-carrier, and that insuch case it will be the advancing movement of the work-spindle whichwill effect the operative engagement of the screw-spindle with the rodof stock, and which will further cause the travel or lengthwise movementof the rod of stock with relation to the rotary cutter to effect thecutting of the thread.

hat I claim as my invention nd desire to secure by Letters Patent is: i

1. A screw-cutting attachment provided with means whereby it may bemounted in the tool-carrier of a screw-machine, said attachmentcomprising a rotary cutter adapted to generate a screw-thread and meansfor rotating the same.

2. A screw-cutting attachment provided with means whereby it may bemounted in the tool-carrier of a screw-machine, said attachmentcomprising a rotary cutter adapted to generate a screw-thread and amaster-screw for revolving said cutter.

3. A screw-cutting attachment provided with means whereby it may bemounted in the tool-carrier of a screw-machine, said attachmentcomprising a rotary cutter adapted to generate a screw-thread and amaster screw for revolving said cutter and controlling the pitch of thethread to be cut thereby.

4. A screw-cutting attachment adapted to be mounted in the tool-carrierof a screwmachine, said attachment comprising a rotary cutter and meansfor rotating said outter from the work carried in the Workspindle of themachine.

5. A screw-cutting attachment adapted to be mounted in the tool-carrierof a screwmachine, said attachment comprising a master-screw adapted tobe rotated by the Work carried in the work-spindle of the machine and arotary cutter operated by said masterscrew.

6. A screw-cutting attachment adapted to be mounted in the tool-carrierof a screwmachine, said attachment comprising a master-screw adapted toengage and be rotated by the rod of stock held in the work-spindle 3 ofthe machine, and a rotary cutter operated by said master-screw.

7. A screw-cutting attachment adapted to be mounted in the tool-carrierof a screwmachine, said attachment comprising'a ro-' tary cutter andmeans for intermittently rotating said cutter from the work carried inthe work-spindle of the machine, the inthe tool-carrier of ascrew-machine, said attachment comprising a master-screw, a worm-wheelin engagement therewith, and a rotary cutter operated by saidworm-wheel.

10. A screw-cutting attachment provided with means whereby it may bemounted in the tool-carrier of a screw-machine, said attachmentcomprising a master-screw, a.

worm-wheel in engagement therewith, and

a rotary cutter operated by said wormwheel, said worm-wheel and rotarycutter being capable of movement lengthwise with relation to saidmaster-screw.

11. A screw-cutting attachment adapted to be mounted in thetool.-carrier of a screwmachine, said attachment comprising .4 a frame,a master-screw mounted to rotate in said frame, and a rotary cuttermounted in said frame and operated by said masterscrew, said frame androtary cutter being capable of movement lengthwise with relation to saidmaster-screw.

12. A screw-cutting attachment adapted to be mounted in the tool-carrierof a screwmachine, said attachment comprising a frame, a master-screwmounted to rotate in said frame, and adapted to be brought by theadvance of said tool-carrier into engagement with the rod of stock hellin the workspindle of themachine and so as to be ro tated thereby, and arotary cutter mounted in said frame and operated by said masterscrew,said frame and rotary cutter having the capacity, to move lengthwisewith relation ,to said master-screw when the latter has been broughtinto engagement with the rod of stock.

FREDERICK E. ANTHONY. Witnesses:

W. H. THURSTON, J H. THURs'roN.

